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Minigun Supergun - An Open Source Supergun

Frank_fjs said:
Looks great, well done. :)

Need the money shot next, i.e. picture of it running.
Click to expand...
Sir ... i must crim the psu harness between Minigun and PSU and i don't know how to match the color to terminations and i don't know long must be the cables i must crimp. can you tell how to do it ? :whistling: will be my first harness made by me
 
AlxUnderBase said:
Frank_fjs said:
Looks great, well done. :)

Need the money shot next, i.e. picture of it running.
Click to expand...
Sir ... i must crim the psu harness between Minigun and PSU and i don't know how to match the color to terminations and i don't know long must be the cables i must crimp. can you tell how to do it ? :whistling: will be my first harness made by me
Click to expand...
I think voltages are silkscreened on the underside of the MiniGun. So dry fit the connector and check with a meter as you go along to be sure.

American wring color scheme is:
  • Ground = Black
  • +5vdc = Red
  • +12vdc = Yellow
  • -5vdc = Blue (typically)
Japanese wiring color scheme (by Sega standards) is:
  • Ground = White
  • +5vdc = Yellow
  • +12vdc = Red
  • -5vdc = Brown
Pick one scheme and go with it (I'm American). You can always go with one wire color as long as you don't cross things up:
  • +5v off PSU to +5v on the MiniGun
  • +12vdc off the PSU to +12vdc on the MiniGun, etc.
As for length, about a 8-10 inches should be the goal so you don't have a rat's nest. But this is situationally dependent on your wall power source location. Do you want a long AC cable to your PSU, and thus a short power cable from your PSU to your MiniGun? Or do you want a short AC cable to your PSU, and therefore need a long power cable from your PSU to you MiniGun? In my best bench setup, I want a long AC cable to the PSU. And I want my PSU close to my MIniGun so I can dial in voltages. So I opt for a short 8" power cable.
 
undamned said:
Frank_fjs said:
I'm aware of the DB15 spacing issue with Undamned encoders. It is a shame, just couldn't space them any further apart due to the compactness of the PCB and other surrounding components.
Click to expand...
If you put the "Test" and "Service" buttons between the DB15 connectors, rather than on the outer edge, it doesn't cost you any real-estate.-ud
Click to expand...
Frank_fjs said:
I'll give that a try, thanks UD.
Click to expand...
That sounds like a great change ... I'm interested in using two undamned decoders as well. I was looking to buy/order a PCB but this possible change might be worth waiting for if it seems possible/easy to change?
 
So I've got one built, but upon going to crimp cables I noticed that the psu I have only has 1 +5v terminal and the board takes two +5v inputs. Should I just pick one or run two wires to the same terminal?
 
ebzero89 said:
So I've got one built, but upon going to crimp cables I noticed that the psu I have only has 1 +5v terminal and the board takes two +5v inputs. Should I just pick one or run two wires to the same terminal?
Click to expand...
Run both +5V wires to the same terminal. Same for the two ground wires.
 
the Goat said:
ebzero89 said:
So I've got one built, but upon going to crimp cables I noticed that the psu I have only has 1 +5v terminal and the board takes two +5v inputs. Should I just pick one or run two wires to the same terminal?
Click to expand...
Run both +5V wires to the same terminal. Same for the two ground wires.
Click to expand...
Thanks! I figured it would be fine but wasn't 100% sure.
 
Thank you for this project! I just received the pcbs and the parts, soldered them and it works nicely.
 

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Hey guys ... does $35/board sound correct for the DigiKey parts? (v1.7 advanced PCB)

Somebody mentioned paying around $60 for three boards worth of parts earlier in this thread...
 
Hey all!
I finished my built of two Minigun advanced boards and tried to set the pots accordingly to:
rsignal said:
...
About the correct levels in video signal I recommend setting the 1K trimpots as 682Ω in series and 318Ω to ground before power on. This divides the 2.2Vpp signal to 0.7Vpp.
Click to expand...
I could achieve 682Ω in line of the signal, but the resistance to ground would be rather in the 230Ω-360Ω Range (one of the pots is only 914Ω instead of slightly above 1k).. so, could somebody answer this question: which I would ask, too now:
arcadeqc said:
What technique should I be using to calibrate the brightness pots? Grab scope and set the values that way? Is there an easy way to get a test pattern to do so?
Click to expand...
 
Do you have an MVS board?

If so, a quick trick that is simple yet extremely accurate when measured properly with a scope...

Enter the service menu / test pattern display. This is perfect as it displays an even amount of red, green and blue on the screen, with white font and no other colours.

Use a multimeter, set to measure DC voltage and probe the RGB 75 Ohm resistors of the Minigun, on the leg closest to the video connector. Other probe to ground, the video connector is grounded so that's one possible spot.

Set each pot to measure 0.45V. This ensures even colour balance and safe attenuation with brightness being optimal. On a completely black screen you'll measure 0.3V (not 0V due to how the THS7374 operates) and on a completely white screen 1.4V. There's your 0.7Vpp. :)
 
Thanks! And yes, I have a MVS board and a scope, will do like you described tomorrow.
 
Which resistors correspond to r, g and b. There are 4: R1-R4. I assume one is for sync. Is R4 sync?
 
@Zitruskeks the values I suggested are an approximation since potentiometers are not very accurate. I use these settings as a starting point to fine tuning.

@Frank_fjs Does that apply to every MVS? I've tested red channel that way in my tv with a MV1FZS and it's at 0.41V, if I set it to 0.45 there is color bleed. It's possible my tv is not well adjusted.
 
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